摘  要：为了研究鱼类疖疮病的生物防治方法，以引起鱼类疖疮病的病原菌杀鲑气单胞菌（Aeromonas salmonicida）为指示菌，从土壤中筛选到对该致病菌有较强拮抗活性的放线菌I6，经16S rRNA分析鉴定为链霉菌（Strptomyces sp.）。链霉菌I6的次级代谢产物对杀鲑气单胞菌具有很强的抗菌活性且对鱼类无毒力，在鱼类疖疮病的治疗和防控中具有应用潜力。为了提高链霉菌I6抗菌活性物质的产量，对该I6菌株进行发酵条件优化，确定其最佳发酵培养基为AM3-1，最适初始pH为7～8，最佳培养时间为5 d，种子液最适菌龄为36 h。所有这些研究结果表明，链霉菌I6对鱼类疖疮病病原菌杀鲑气单胞菌有显著抑制作用，在渔业生物防治中有潜在的开发应用价值。
关键词：杀鲑气单胞菌；放线菌；拮抗作用；次级代谢产物；发酵条件优化
中图分类号：Q939.9　　　　　　文献标志码：ADOI：10.3969/j.issn.1007-7146.2021.04.011

Abstract: In order to study the biological control methods of fish furunculosis, actinomycete I6 strain with strong antagonistic activity was screened from soil by using the fish furunculosis pathoge Aeromonas salmonicida as indicator strain. 16S rRNA analysis indicates that it is a Streptomyces sp. strain. The secondary metabolites produced by I6 exhibit strong antibacterial activity to A. salmonicida in vitro, and no obvious adverse effect on fish was observed. This result provides a reference for the treatment and prevention of A. salmonicida. In order to enhance the yield of the antibacterial active substance of I6, the fermentation conditions of the I6 strain were optimized. The results showed that the optimal fermentation medium is determined to be AM3-1 with initial pH of 7～8, and the optimal cultivation time is 5 days. The optimum bacterial age for seed liquid is 36 h. All these results shows that I6 has a significant inhibitory effect on the growth of fish furunculosis pathogen A. salmonicida, and has potential development and application value in fishery biocontrol.
Key words: Aeromonas salmonicida; actinomycetes; antagonistic effect; secondary metabolites; optimization of fermentation conditions
（Acta Laser Biology Sinica, 2021, 30(4): 370-377）